A pastoral view spreads across Aio district in Yamaguchi City by the coast of the Seto Inland Sea. "Yamaguchi City Aio Mega-Solar (MS) Power Plant" with an output of 1.4MW, which West Holdings Corp constructed and completed in August 2013, is located in the plain that faces the sea (Fig. 1). It appears to be an average power generation facility with an output of around 2MW in Yamaguchi Prefecture, where a number of mega (large-scale) solar power plants have been constructed one after another. However, this plant features "Japan's first" something.

That "something" is the international standard certification that this plant obtained from a third party for the first time among mega-solar power plants in Japan. Starting in November 2013, TUV SUD Japan Ltd (Shinjuku-ku, Tokyo), the Japanese unit of German TUV SUD AG, engaged in verification and inspection, examined the plant and granted the third-party authorization Feb 14, 2014 (Fig. 2) in compliance with the International Electrotechnical Commission's (IEC) "IEC62446."

IEC62446 is an international standard that describes the minimum requirements for inspection, commissioning tests and system documentation that have to be fulfilled when the grid connected PV system is completed. Unlike a standard for each item such as a solar panel, this standard is characterized by evaluating the eligibility and reliability of the whole photovoltaic (PV) power generation system.

Executive Officer Kenji Araki of West Holdings cited two factors behind the authorization of the international standard certification by a third party. The company has constructed PV power generation systems for more than 30 years since its foundation.

"Compared with the projects for home use based on systems of up to several kilowatts, a mega-solar power plant's output is by far larger," he said, explaining one of the two factors. "Partly because the market has expanded rapidly, we have been accumulating technology while studying and moving forward at the same time. We wanted to confirm that our design and construction methods are not incorrect by having a third party evaluate them in compliance with international standards."

"We aim to differentiate itself by obtaining an international verification/test company's authorization that our mega-solar power plant design and construction are of high quality and reliable, partly to boost our bankability (loan qualification) in view of future development," Araki said, describing the other factor.